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San Raffaele Cimena, Italy

The EARLIER (Evaluation of MimpARa in incident hemodiaLysis patIEnts with secondaRy hyperparathyroidism; SHPT) observational postmarketing surveillance study evaluated incident hemodialysis patients (< 1 year dialysis vintage; n = 146) receiving cinacalcet in Austrian clinical practice. Despite intervention with vitamin D sterols and phosphate binders, 24 % had already developed severe SHPT (intact parathyroid hormone (iPTH) > 800 pg/mL) at baseline. After cinacalcet was started, median iPTH decreased substantially, from 611 pg/mL to 251 pg/mL (median decrease 58 % [IQR − 36 to − 78 %] at 12 months. Overall, 36 % of patients achieved the Kidney Disease Outcomes Quality Initiative (K/DOQI) target range (150–300 pg/mL) for iPTH; this included 35 % of those with severe SHPT at baseline. Serum phosphorus (P), calcium (Ca) (corr), and Ca (corr) × P also decreased, with 43, 34, and 62 % of patients, respectively, reaching K/DOQI targets at 12 months. Thus, in this observational study, mineral metabolism in incident dialysis patients with SHPT improved after starting cinacalcet. © 2015, Springer-Verlag Wien.

Vergani A.,Medical School | Tezza S.,Medical School | D'Addio F.,Medical School | Fotino C.,University of Miami | And 19 more authors.
Circulation | Year: 2013

Background: Heart transplantation is a lifesaving procedure for patients with end-stage heart failure. Despite much effort and advances in the field, current immunosuppressive regimens are still associated with poor long-term cardiac allograft outcomes, and with the development of complications, including infections and malignancies, as well. The development of a novel, short-term, and effective immunomodulatory protocol will thus be an important achievement. The purine ATP, released during cell damage/activation, is sensed by the ionotropic purinergic receptor P2X7 (P2X7R) on lymphocytes and regulates T-cell activation. Novel clinical-grade P2X7R inhibitors are available, rendering the targeting of P2X7R a potential therapy in cardiac transplantation. Methods and Results: We analyzed P2X7R expression in patients and mice and P2X7R targeting in murine recipients in the context of cardiac transplantation. Our data demonstrate that P2X7R is specifically upregulated in graft-infiltrating lymphocytes in cardiac-transplanted humans and mice. Short-term P2X7R targeting with periodate-oxidized ATP promotes long-term cardiac transplant survival in 80% of murine recipients of a fully mismatched allograft. Long-term survival of cardiac transplants was associated with reduced T-cell activation, T-helper cell 1/T-helper cell 17 differentiation, and inhibition of STAT3 phosphorylation in T cells, thus leading to a reduced transplant infiltrate and coronaropathy. In vitro genetic upregulation of the P2X7R pathway was also shown to stimulate T-helper cell 1/T-helper cell 17 cell generation. Finally, P2X7R targeting halted the progression of coronaropathy in a murine model of chronic rejection as well. Conclusions: P2X7R targeting is a novel clinically relevant strategy to prolong cardiac transplant survival. © 2012 American Heart Association, Inc.

Vergani A.,Harvard University | Gatti F.,Harvard University | Gatti F.,University of Salento | Lee K.M.,Harvard University | And 16 more authors.
Cell Transplantation | Year: 2015

The role of the novel costimulatory molecule TIM4 in anti-islet response is unknown. We explored TIM4 expression and targeting in Th1 (BALB/c islets into C57BL/6 mice) and Th2 (BALB/c islets into Tbet-/- C57BL/6 mice) models of anti-islet alloimmune response and in a model of anti-islet autoimmune response (diabetes onset in NOD mice). The targeting of TIM4, using the monoclonal antibody RMT4-53, promotes islet graft survival in a Th1 model, with 30% of the graft surviving in the long term; islet graft protection appears to be mediated by a Th1 to Th2 skewing of the immune response. Differently, in the Th2 model, TIM4 targeting precipitates graft rejection by further enhancing the Th2 response. The effect of anti-TIM4 treatment in preventing autoimmune diabetes was marginal with only minor Th1 to Th2 skewing. B-Cell depletion abolished the effect of TIM4 targeting. TIM4 is expressed on human B-cells and is upregulated in diabetic and islettransplanted patients. Our data suggest a model in which TIM4 targeting promotes Th2 response over Th1 via B-cells. The targeting of TIM4 could become a component of an immunoregulatory protocol in clinical islet transplantation, aiming at redirecting the immune system toward a Th2 response. © 2015 Cognizant Comm. Corp.

D'Addio F.,Harvard University | La Rosa S.,Ospedale di Circolo | Maestroni A.,Transplant Medicine | Jung P.,Barcelona Institute for Research in Biomedicine | And 22 more authors.
Cell Stem Cell | Year: 2015

Summary The role of circulating factors in regulating colonic stem cells (CoSCs) and colonic epithelial homeostasis is unclear. Individuals with long-standing type 1 diabetes (T1D) frequently have intestinal symptoms, termed diabetic enteropathy (DE), though its etiology is unknown. Here, we report that T1D patients with DE exhibit abnormalities in their intestinal mucosa and CoSCs, which fail to generate in vitro mini-guts. Proteomic profiling of T1D+DE patient serum revealed altered levels of insulin-like growth factor 1 (IGF-I) and its binding protein 3 (IGFBP3). IGFBP3 prevented in vitro growth of patient-derived organoids via binding its receptor TMEM219, in an IGF-I-independent manner, and disrupted in vivo CoSC function in a preclinical DE model. Restoration of normoglycemia in patients with long-standing T1D via kidney-pancreas transplantation or in diabetic mice by treatment with an ecto-TMEM219 recombinant protein normalized circulating IGF-I/IGFBP3 levels and reestablished CoSC homeostasis. These findings demonstrate that peripheral IGF-I/IGFBP3 controls CoSCs and their dysfunction in DE. © 2015 Elsevier Inc.

Ben Nasr M.,Harvard University | Vergani A.,Harvard University | Avruch J.,Harvard University | Liu L.,Harvard University | And 13 more authors.
Acta Diabetologica | Year: 2015

Aims: Mesenchymal stem cells (MSCs) are multipotent cells with immunomodulatory properties. We tested the ability of MSCs to delay islet allograft rejection. Methods: Mesenchymal stem cells were generated in vitro from C57BL/6 and BALB/c mice bone marrow, and their immunomodulatory properties were tested in vitro. We then tested the effect of a local or systemic administration of heterologous and autologous MSCs on graft survival in a fully allogeneic model of islet transplantation (BALB/c islets into C57BL/6 mice). Results: In vitro, autologous, but not heterologous, MSCs abrogated immune cell proliferation in response to alloantigens and skewed the immune response toward a Th2 profile. A single dose of autologous MSCs co-transplanted under the kidney capsule with allogeneic islets delayed islet rejection, reduced graft infiltration, and induced long-term graft function in 30 % of recipients. Based on ex vivo analysis of recipient splenocytes, the use of autologous MSCs did not appear to have any systemic effect on the immune response toward graft alloantigens. The systemic injection of autologous MSCs or the local injection of heterologous MSCs failed to delay islet graft rejection. Conclusion: Autologous, but not heterologous, MSCs showed multiple immunoregulatory properties in vitro and delayed allograft rejection in vivo when co-transplanted with islets; however, they failed to prevent rejection when injected systemically. Autologous MSCs thus appear to produce a local immunoprivileged site, which promotes graft survival. © 2015, Springer-Verlag Italia.

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